XZ Utils Licensing
Different licenses apply to different files in this package. Here
is a rough summary of which licenses apply to which parts of this
package (but check the individual files to be sure!):
- liblzma is in the public domain.
- xz, xzdec, and lzmadec command line tools are in the public
domain unless GNU getopt_long had to be compiled and linked
in from the lib directory. The getopt_long code is under
- The scripts to grep, diff, and view compressed files have been
adapted from gzip. These scripts and their documentation are
under GNU GPLv2+.
- All the documentation in the doc directory and most of the
XZ Utils specific documentation files in other directories
are in the public domain.
- Translated messages are in the public domain.
- The build system contains public domain files, and files that
are under GNU GPLv2+ or GNU GPLv3+. None of these files end up
in the binaries being built.
- Test files and test code in the tests directory, and debugging
utilities in the debug directory are in the public domain.
- The extra directory may contain public domain files, and files
that are under various free software licenses.
You can do whatever you want with the files that have been put into
the public domain. If you find public domain legally problematic,
take the previous sentence as a license grant. If you still find
the lack of copyright legally problematic, you have too many
As usual, this software is provided "as is", without any warranty.
If you copy significant amounts of public domain code from XZ Utils
into your project, acknowledging this somewhere in your software is
polite (especially if it is proprietary, non-free software), but
naturally it is not legally required. Here is an example of a good
notice to put into "about box" or into documentation:
This software includes code from XZ Utils <http://tukaani.org/xz/>.
The following license texts are included in the following files:
- COPYING.LGPLv2.1: GNU Lesser General Public License version 2.1
- COPYING.GPLv2: GNU General Public License version 2
- COPYING.GPLv3: GNU General Public License version 3
Note that the toolchain (compiler, linker etc.) may add some code
pieces that are copyrighted. Thus, it is possible that e.g. liblzma
binary wouldn't actually be in the public domain in its entirety
even though it contains no copyrighted code from the XZ Utils source
If you have questions, don't hesitate to ask the author(s) for more